Need insurance for MMA classes at local community center

I have everything set up and ready to go to start teaching kickboxing and BJJ classes at my local community center. They're not even going to charge me to rent the room! I just need to have my own insurance.
I imagine there's a good chance somebody on here has done something similar and might be able to point me towards a good affordable policy.
Also if I'm charging my students just enough to break even and any extra cash just gets spent on gear for the group. Do you think I should have a business license as well? This is in the state of Nevada.
Not sure if this is the right forum.

I don't know about running an (M)MA school, but I can tell you that you definitely want the business license and corporation, etc., in pretty much any business venture, even not-for-profit. The corporate structure, if done right, will protect your personal assets in case you do ever have legal issues. I can also tell you, unfortunately, that if you are successful you WILL have people trying to sue you. Get incorporated, get the license(s) you need, and stay above board with all your business. See also "ask an attorney."

Omega Pointed me in the right direction for insurance, and it's not even that expensive, but I do need to have a business license to get the insurance.
So it looks like I need to do it completely legit or not do it at all.
Thanks for the comments guys, we're in Stateline NV, hit us up if you're ever in Tahoe for a ski/snowboard trip. Actually hit me up when you're planning your trip, my wife manages a local hotel.https://www.facebook.com/SouthShoreCombatClub